Prostheta Posted October 30, 2018 Report Share Posted October 30, 2018 You and I see different things all of the time, Scott! I immediately see (or calculate) the clamping pressure and distribution. More importantly, a single line down the centre wouldn't apply pressure at the edges as much as the centre unless it's a sprung joint (slightly concave on one face....not reasonable at this scale or narrow width) whilst two is excellent. The ultimate bond strength (assuming perfect mating faces) will be more than adequate for the end use whereas the cosmetic glue line might be a little more visible than as not. It should still be a really fine result when it comes out of the clamps and is cleaned up. You'd be surprised how many people in industry aren't aware of how to run the numbers either you know. People are surprised how seamless my joins are when laminating and think I'm crazy for using 60 F-clamps and noting that 90 would be better. 1 Quote Link to comment Share on other sites More sharing options...
Norris Posted October 30, 2018 Author Report Share Posted October 30, 2018 I did have a few comments at class when I clamped it up I don't run the numbers, but go on the premise that you can't clamp it too much but can clamp it too little 1 Quote Link to comment Share on other sites More sharing options...
Andyjr1515 Posted October 30, 2018 Report Share Posted October 30, 2018 1 hour ago, Prostheta said: You and I see different things all of the time, Scott! I immediately see (or calculate) the clamping pressure and distribution. More importantly, a single line down the centre wouldn't apply pressure at the edges as much as the centre unless it's a sprung joint (slightly concave on one face....not reasonable at this scale or narrow width) whilst two is excellent. The ultimate bond strength (assuming perfect mating faces) will be more than adequate for the end use whereas the cosmetic glue line might be a little more visible than as not. It should still be a really fine result when it comes out of the clamps and is cleaned up. You'd be surprised how many people in industry aren't aware of how to run the numbers either you know. People are surprised how seamless my joins are when laminating and think I'm crazy for using 60 F-clamps and noting that 90 would be better. Whereas I, at first employing my 'proper' engineering qualifications, would start by trying to calculate how many clamps of what type would be necessary. But soon, realising that I never actually did understand the 'proper' engineering I was taught, I would probably revert to my more usual approach of employing 'popular' engineering and just hitting the thing with a bl**dy big hammer enough times for it to assume roughly the correct shape while being clamped with clothes pegs. Quote Link to comment Share on other sites More sharing options...
Prostheta Posted October 30, 2018 Report Share Posted October 30, 2018 You can....however it would take a lot of effort and no cauls to overpressure an area. 1 Quote Link to comment Share on other sites More sharing options...
Andyjr1515 Posted October 30, 2018 Report Share Posted October 30, 2018 1 hour ago, Prostheta said: You can....however it would take a lot of effort and no cauls to overpressure an area. This all depends which one of our replies you are responding to! 1 Quote Link to comment Share on other sites More sharing options...
ScottR Posted October 31, 2018 Report Share Posted October 31, 2018 22 hours ago, Prostheta said: You and I see different things all of the time, Scott! I immediately see (or calculate) the clamping pressure and distribution. I actually do wonder about that every time I see a string of Irwins too......after the marching hammer thing. But I says to myself, Carl will pick up on that end of the subject. I like to use two inch thick cauls and crank the piss out of heavy clamps applying the cone of pressure rule for the spacing. Irwins on something as thin as a fretboard always worries me, because I can't squeeze them anywhere near as tight as I can crank a C-clamp. On the other hand I've seen many guys line them up on the fretboard just like @Norris did hear and get perfectly lovely glue joints so it must work. Quote Link to comment Share on other sites More sharing options...
Prostheta Posted October 31, 2018 Report Share Posted October 31, 2018 Quick clamps only develop a couple of hundred PSI. Nothing to be scared of. Quote Link to comment Share on other sites More sharing options...
ScottR Posted November 1, 2018 Report Share Posted November 1, 2018 19 hours ago, Prostheta said: Quick clamps only develop a couple of hundred PSI. Nothing to be scared of. I'm assuming a couple hundred PSI is enough....as long as it covers all the square inches? What would be the minimum PSI that you could expect to get an invisible glue line from, assuming your prep work is adequate and typical as opposed to perfectly mated surfaces? SR Quote Link to comment Share on other sites More sharing options...
Prostheta Posted November 1, 2018 Report Share Posted November 1, 2018 Depends on the softest of the two woods, the direction of cut and thickness. I aim for 200-400 from the softest to the hardest hardwoods, which is the simplest way to view the numbers. Realistically, quarter to half of ideal gets you an optimal bond when pressure is distributed evenly with cauls and beyond there it's all about cosmetics. Some woods show it more than others as well. Khaya for example, is excellent at 200-250PSI. Invisible joins are easy. Consider a body blank at 16" x 1,5" or 24in of area. That's 4800-6000lbs, or 5-6 big heavy duty F-clamps. Three good table bar clamps. Half of that still gets you a result, quarter maybe not so. Up those values to neck blank, top or fingerboard area and the numbers go up a lot because of surface area. If the join isn't critical - such as a top - you can concentrate pressure around the visible seam to get the best appearance whilst getting "what you can" in the middle where quarter-half is adequate but not ideal. A fingerboard benefits from even and adequate pressure of course. Does this make things clear as mud? Quote Link to comment Share on other sites More sharing options...
ScottR Posted November 1, 2018 Report Share Posted November 1, 2018 At least that clear. SR 1 Quote Link to comment Share on other sites More sharing options...
Norris Posted November 5, 2018 Author Report Share Posted November 5, 2018 I managed to steal a couple of hours at the weekend and tidied up a little with a cabinet scraper Quote Link to comment Share on other sites More sharing options...
ScottR Posted November 5, 2018 Report Share Posted November 5, 2018 Your fretboard is not radiused yet? I foresee some scraped knuckles in your future. SR Quote Link to comment Share on other sites More sharing options...
mistermikev Posted November 5, 2018 Report Share Posted November 5, 2018 norris, your work is really something else. I read your thread in reverse from this last pick and was like... how did he cut that body like that with the neck underlay... mystery solved. looking at it I never would have guessed it was a sep piece. small detail but executed like a pro. nice job. 1 Quote Link to comment Share on other sites More sharing options...
Norris Posted November 6, 2018 Author Report Share Posted November 6, 2018 18 hours ago, ScottR said: Your fretboard is not radiused yet? I foresee some scraped knuckles in your future. SR No That joy is yet to come I intend to keep my fingers on top of the sanding block rather than wrapped around it Quote Link to comment Share on other sites More sharing options...
Norris Posted November 20, 2018 Author Report Share Posted November 20, 2018 The workshop has been closed for a couple of weeks for repairs to the extraction system. We were back last night so I put an initial rough radius on the board. I have an inlay to do at the 12th fret, so this will do for now. A straight edge, flat caul with 80 grit stuck on with CA, and a radius gauge (old skool again)... I also started tidying and trimming the shoulders of the headstock on the spindle sander 2 Quote Link to comment Share on other sites More sharing options...
Andyjr1515 Posted November 20, 2018 Report Share Posted November 20, 2018 Looking good 1 Quote Link to comment Share on other sites More sharing options...
Norris Posted November 26, 2018 Author Report Share Posted November 26, 2018 I may have mentioned previously that I am currently spending 2 hours a week building this guitar. This week's thrilling instalment is... erm... Drilling 2 holes There again, they are quite important holes. For now they are "hogged out" with a 10mm forstener bit until such time as I can find a 1/2" drill bit. I'm sure there's one somewhere amongst my uncle's old stuff. Probably all Whitworth though 1 Quote Link to comment Share on other sites More sharing options...
ScottR Posted November 27, 2018 Report Share Posted November 27, 2018 Progress is progress. @Prostheta would be proud of the painstaking care you are displaying with this build. SR 1 1 Quote Link to comment Share on other sites More sharing options...
Prostheta Posted November 28, 2018 Report Share Posted November 28, 2018 "Would" I'm not gone!! Haha Yes, it's lovely clean and well considered work. Quote Link to comment Share on other sites More sharing options...
mistermikev Posted November 28, 2018 Report Share Posted November 28, 2018 nice, got yer stud holes in. Your progress is probably on parr with mine... I keep thinking my finish is ready and then burning through and building up again. Last night I was about to say screw it and shoot some poly but I walked away and this am started building it again. Looking at your build I keep thinking "a lp double cut IS something I could use". Looking very nice. (one of everything please) 1 Quote Link to comment Share on other sites More sharing options...
Norris Posted November 28, 2018 Author Report Share Posted November 28, 2018 Well at least it might give inspiration to the casual lurker who thinks they haven't got time to build a guitar. You can put whatever time you can spare into it. Just keep chipping away. Once I've finished rebuilding the engine I'll hopefully be able to speed things up a bit. Gigging at the weekend regularly doesn't help with either Thanks for the encouragement folks 2 Quote Link to comment Share on other sites More sharing options...
beltjones Posted November 29, 2018 Report Share Posted November 29, 2018 There are two types of people. Well, maybe more, but two types I'll describe here. One type (like me) says, "I only have two hours to work on the guitar this week, I better rush everything." The other type (like Norris) says, "I only have two hours to work on the guitar this week, I'm going to drill two holes as perfectly as I can." I need to be more like Norris. 1 1 Quote Link to comment Share on other sites More sharing options...
Prostheta Posted November 29, 2018 Report Share Posted November 29, 2018 True true. The people that keep chipping away get more done than those such as myself who plan endlessly, then wonder where the time is coming from, or where it has gone! 3 Quote Link to comment Share on other sites More sharing options...
Norris Posted December 3, 2018 Author Report Share Posted December 3, 2018 So, one quick and cheap Ebay purchase later, we have a 1/2" drill bit. And we have some correct sized holes Although the body wood looks mahogany-ish, it's relatively less dense - lighter and softer. I can't remember the name of it. To make sure the inserts sit firmly I wicked CA around the holes (the above picture was before the CA wicking) Then it was pretty straightforward to clamp my template on and route the bridge pickup cavity. The depth was adjusted to the neck angle - 15mm this time. (Only the pickup covers shown there. I've not sunk them that deep!) Now you may be wondering what that small hole is doing just in front of the bridge pickup. Erm, it's a slight miscalculation screwing the template to the body blank when I first shaped it. Oh well. There are options though, depending on which finish we settle on. If painted solid colour, I'll plug it and it will be blended with the grain filling. Whether painted or not there's a fair chance it will have a scratch plate covering it. Personally my preferred option is to stay with a natural/dyed finish, and I have something in mind for that option too 1 Quote Link to comment Share on other sites More sharing options...
curtisa Posted December 6, 2018 Report Share Posted December 6, 2018 On 12/4/2018 at 9:40 AM, Norris said: Now you may be wondering what that small hole is doing just in front of the bridge pickup. I had assumed it was a beauty spot Fill it with abalone and call it custom inlay. Take that, you philistines! Quote Link to comment Share on other sites More sharing options...
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